CrownsCrowns are used to restore fractured, broken down, or structurally weakened teeth. They are essentially a new exterior for your tooth. The outer layer of the crown is constructed of matching shade of porcelain. Some crowns incorporate an inner layer of precious metal to strengthen the crown. Most newer crowns use a computer-milled zirconia ceramic core as the strong base layer. In some cases, such as for teeth in areas that are not visible during a smile, the biting surface may be constructed with a metal exterior. Some crowns are constructed exclusively from porcelain. Most finished crowns are indistinguishable from a natural tooth. The process involves preparation of the tooth, to make room for the crown material. A temporary crown is fabricated, and an impression of the tooth is formed. The dental laboratory then constructs a precision fitting, natural looking crown. The second visit involves fitting and cementing the crown over your natural, prepared tooth. The crown is not removable once placed. Many years of service can be expected from a crown, assuming good brushing and flossing and regular professional maintenance.